Strigolactones (SLs) are plant hormones with pivotal roles in plant growth. Being conserved among all plant species, they’ve been recruited by plant-associated microbes as plant-derived molecules allowing microbes to detect plants, exchange signals and establish interactions with them. In this review, Lanfranco et al. guide us along a trip following SLs in the plant, fungal and bacterial world. There is a flow of strigolactones from the roots to remote soil niches, and at each level the SLs have a different role and action. Within the plant, they regulate shoot branching and root system architecture. In the soil they are detected by arbuscular mycorrhizal fungi and stimulate hyphal branching and active metabolism. Finally, obligate endobacteria living within the mycorrhizal fungi activate a ROS burst upon detection of SLs. This review shows that SLs act as as universal coin among different kingdoms. (Summary by Marco Giovannetti) J. Exp. Bot. 10.1093/jxb/erx432